The queen would be head of state with the Governor General being her representative in Canada. However they are purely figure heads as the supreme court of Canada is no longer answerable to the British privy council since about 1949.
I believe @mallard has it right in that jurisdiction.
In Australia (at variance to all other Commonwealth countries I am aware) the Head of State is the Governor General in whom all the reserve powers are vested and is also head of the armed services. The GG is appointed by the Queen of Australia on the advice of the Prime Minister.
Federation happened in 1901, not 1900, IIRC.
Here in Ireland, we arguably spend more time amending our Constitution then we do invoking it. (11 amendments in the past 10 years, including ones to allow abortion on demand and enshrining the right to same sex marriage).
The Constitution is certainly regularly invoked in the legal system, by people who believe their rights under it have been compromised. Indeed these days our Supreme Court’s main function is to deal with Constitutional challenges and interpretation.
There’s also a very small incidence of people (usually on the extreme left or extreme right) who will regularly claim something or other is either unconstitutional or required by the constitution. These claims are usually ludicrous and essentially demonstrate that those making them haven’t read the Constitution. (They often invoke rights that the Constitution doesn’t mention or claim a right is absolute when it’s clearly qualified).
There was a great deal of consideration went into the Australian Constitution, but to the average Australian at the time, what was being considered were the terms of Federation – the new constitution for the joined states. They weren’t leaving the empire. However, each state had to pass enabling acts, and the constitution was put to the people in the Commonwealth Constitution Bill referendums.
Some of the states (Fiji, New Zealand) decided not join the Federation.
The constitution is also technically a law passed by the British parliament, but that was never all it was – although even that is an issue to the substantial number of Australians.
Thais do. But then, they change theirs from scratch every so often.
I’ll give the Founding Fathers credit that they did a very good job considering how little prior art they had available to use as examples. But unsurprisingly for such a prototype, it’s very poorly made, compared to many later examples. I mean, the Founders didn’t even realize that such a thing as political parties would ever form, even though they already existed at the time.
And as an aside on the topic of “tearing the whole thing up and starting from scratch”, the Montana constitution actually has a provision that, every 20 years, the voters of the state must vote on whether to do exactly that. I found that amusing, when I voted against it.
Sure, later examples may be more elegant. But they can freely crib from the groundwork done by multiple other countries. The reality is the American Constitution has largely stood the test of time and been quite prescient. Why do you think it’s poorly made?
However, the school of thought - we need to know what the original founders might have thought about complex modern issues - confuses me a little. It seems to be using the pretext of pretending to know the unknowable to justify whatever particular view one already favours. Better to decide without the malarkey. Dagnabbit. Can’t blame that on the founders.
Canada’s constitution WAS an act of British parliament; in 1982 it was “patriated,” made entirely Canadian, and elevated to the status of a true constitution; it can’t just be changed or repealted by an act of Canada’s Parliament.
This is certainly my impression as well. When I watch all of the stuff going on in the US these days and I see people constantly invoking the constitution, my thought tends to be “FFS, it’s not magic! It’s just a policy document written on spiffy paper (or whatever it is) etc etc”.
In my early days in the Canadian Navy back in the '80s our ship had two USN midshipmen or ensigns assigned to us for the summer, as sort of an exchange/professional development thing. I got into a discussion with one of them about gun control that went sort of like this:
USN guy: “You can’t have gun control! It’s against the constitution”
Velomont: “What if the constitution’s wrong?”
USN guy: “The constitution’s never wrong!”
For my day-to-day stuff I don’t need to invoke or know my constitution any more than I need to be familiar with my refrigerator manual.
The Irish Free State Constition was enacted by Dail Eireann “sitting as a Constituent Assembly in this Provisional Parliament”. The legislation provided that “the Constitution set forth in the First Schedule hereto annexed shall be the Constitution of The Irish Free State”.
Not satisfied with this, the UK Parliament passed its own Act, also providing that the same Constitution “shall be the Constitution of The Irish Free State”.
Thus, as far as the UK courts were concerned, the IFS constitution was conferred by the UK parliament, and that was the foundation of its legitimacy. But as far as the Irish courts were concerned, the IFS constitution was enacted by the Irish Parliament, and that was the foundation of its legitimacy.
The IFS Consitution was replaced in 1937 with a wholly new Constitution which was not conferred or adopted by parliament but was enacted by the people, by way of referendum. Formally, this was a revolutionary act since neither the IFS constitution nor any legislation made under it conferred any legislative capacity on the people.
To loop back to the OP’s reference to the Jim Jefferies stand-up routine:
USN guy: “You can’t change the Constitution”.
Velomont: “Yes you can, it’s called an Amendment.”
In the UK we don’t have a constitution, just a bundle of precedents and conventions. It isn’t usually part of daily political debate, because there isn’t anything in law to stop parliament responding to sufficient political pressure that “There ought to be a law”.
Except to extent that there are law cases that refer either to the Human Rights Act (which allows for the European Convention on Human Rights to be applied in British courts), or some common law or legal precedent.
The latter came to prominence over how the government and parliament respectively should deal with Brexit, both of which ended up with the Supreme Court ruling, in effect, that Parliament was the supreme element in “the Crown in Parliament” and the government couldn’t just do what they want regardless.
Otherwise, the most common way in which anyone refers to some “constitutional” issue is usually a tabloid press hooha about something arcane to do with the royals, that usually isn’t substantively constitutional (in the sense of how the country’s governance works) at all, more a question or custom and practice.
As Dr. House said to his Australian protege, “You put the Queen on your money. That makes you British”
No, those people (by which I mean ignorami) generally know two Amendments - the First, and Second. And their knowledge generally interprets them as “I can say and do what I want” and “No one can take away my guns”. Some of the more knowledgeable ones may understand “pleading the Fifth” as they don’t have to testify in court. They might even know that it refers to the Fifth Amendment.
Ironically, these people might also consider taxation to be a form of “theft”, even though it’s covered by the Sixteenth Amendment.
In South Africa, it’s only in the last 26 years (since 1994) that we’ve had a constitution (and a Bill of Rights) that is superior to ordinary law, so that other laws can be struck down for being unconstitutional. And yet in that time I’d say that the idea of invoking the constitution has become very common. At my more cynical, I’d say “that must be unconstitutional” has become almost shorthand for “the government did something I don’t like”.
There aren’t any important passages of our constitution that ordinary people could recite, though, it’s more a reference to the ideas - dignity, equality, free speech, etc.
Who says American ways are not spreading around the world? 
That is a classic! Extremely funny
We have equivalents, usually on the more extreme right (who like to get their martyrdom in first). My view is that freedom of speech is not (a) freedom from social consequences, nor (b) an entitlement to anyone else’s megaphone.
And many Australians would have agreed with him. (At least when I was younger). So they really wanted to get the Queen off the money. But they couldn’t, because everybody uses the money, and they were rather fond of it. So they thought, ‘at least we could change our flag’ (The British use the upper left quadrant of our flag as their flag). But they couldn’t, because everybody knows the flag, and it had too much local support.
So then they thought – the constitution. “Nobody cares about the constitution. At least we could get the Queen out of the constitution.”. And they were right - nobody cared about taking the Queen out of the constitution. But they were faced with the problem of what to put into the constitution to replace the hole – and that’s where it fell over. Nobody agreed about what to put into the constitution. So the Queen’s still in there too.